https://blog.yusukeikoma.com/tags/durable-objects/Recent content in durable-objects on Ikoma's BlogHugoen-usThu, 24 Sep 2026 21:33:45 +0900https://blog.yusukeikoma.com/posts/durable-object-alarm-retries-six-times-then-stops/Thu, 24 Sep 2026 21:33:45 +0900https://blog.yusukeikoma.com/posts/durable-object-alarm-retries-six-times-then-stops/A Durable Object has one alarm, runs it at least once, and retries a failing handler with backoff up to six times. After that nothing wakes the object again. A walkthrough of a lease-expiry ledger that survives all three: a table as the source of truth, a constructor that re-arms the alarm, and an effect that tolerates being run twice. Run on local workerd, with the documented limits quoted from Cloudflare.https://blog.yusukeikoma.com/posts/durable-objects-websocket-hibernation/Tue, 22 Sep 2026 13:39:45 +0900https://blog.yusukeikoma.com/posts/durable-objects-websocket-hibernation/Cloudflare’s docs say hibernation keeps WebSocket connections open and discards in-memory state. This post runs a small Durable Object under local workerd and watches exactly what that means: the socket stays OPEN, the constructor runs again on the next message, class fields reset, attachments survive only if you serialize them, and a pending timer or the standard WebSocket API quietly turns hibernation off. Production behaviour and billing are not tested.https://blog.yusukeikoma.com/posts/batching-and-bounded-frames-on-a-metered-relay/Wed, 19 Aug 2026 12:47:53 +0900https://blog.yusukeikoma.com/posts/batching-and-bounded-frames-on-a-metered-relay/When every WebSocket message costs money and every frame has a hard cap, you need batching with independent flush triggers, a single-frame threshold below the cap, bounded chunking, and capability flags that survive mixed-version rollouts. The sharp edges are ordering on shutdown and a zero value that disappears from the wire.